docs: def get_thumbnail_of_file(image_name, width):
      """Return the file contents of the thumbnail of the given file."""
      hdr = {'User-Agent': 'Python urllib2'}
      url = make_thumb_url(image_name, width)
      req = urllib2.Request(url, headers=hdr)
      try:
          logging.debug("Retrieving %s", url)
          opened = urllib2.urlopen(req)
          extension = opened.headers.subtype
          return opened.read(), make_thumbnail_name(image_name, extension)
      except urllib2.HTTPError, e:
          message = e.fp.read()
          raise get_exception_based_on_api_message(message, image_name)